This invention relates to medical devices, and more particularly to an automatic inserter for installing an angled or low-profile infusion set in the skin of a person to subcutaneously administer medication or other substances beneficial to health.
Frequent or continuous subcutaneous injection of medication such as insulin is often accomplished through the use of an infusion set or injection port which may remain in place for several days. In the case of frequent injections, the infusion set reduces the need to constantly puncture the skin, thereby minimizing the risk of infection and the formation of scar tissue. For continuous subcutaneous delivery of medication through portable insulin pumps or the like, an infusion set is often used to provide a method of temporarily detaching the pump and fluid line for activities such as dressing or bathing. It is also desirable in this instance to detach the fluid line from the pump as close to the injection site as possible, thereby leaving a relatively small component attached to the body which minimizes any interference during dressing, bathing or other activities.
Angled infusion sets, such as disclosed in my copending U.S. Provisional patent application Ser. No. 09/625,245 filed on Jul. 25, 2000, the disclosure of which is herein incorporated by reference, are especially advantageous due to their low profile during use. See also U.S. Pat. No. 5,522,803 issued to Tiessen-Simoney on Jun. 4, 1996. Such devices include a manual inserter with a handle and an introducer needle that attach to a cannula housing. A self-adhesive pad on the bottom surface of the cannula housing secures the housing to the skin of a person. To insert the infusion set, the user grasps the handle with one hand while pinching a fold of skin between the thumb and forefinger of the other hand. The introducer needle together with the outer end of the cannula are then pushed by the user into the fold of skin. The introducer needle is removed from the cannula housing leaving the cannula inserted in the subcutaneous layer. The housing is then adhesively secured to the skin. A tubing connector from an insulin pump can then be connected to the cannula housing to deliver insulin or other substances to the subcutaneous layer.
While this process is relatively straightforward for more experienced persons, it does require manual dexterity. In addition, the cannula may become kinked during an improper installation and impede the flow of insulin, or may be positioned in an improper skin layer. Surrounding tissue may also be damaged during attempts to correctly position the cannula, causing added pain and trauma to a user. Many users prefer to avoid the trauma associated with self-inserting the introducer needle and cannula into their bodies.
Accordingly, it would be desirous to provide an automatic inserter for angled or low-profile infusion sets, thereby assuring the correct placement of the cannula in the subcutaneous layer at the correct angle while minimizing the trauma associated with cannula installation.